Coworker with KTM SX

[MX Quad Dad]

I have a co-worker that bought his son a KTM to race, his son's friend also owns one. He claims he does all of the maintanace by the book with quality oil and parts. I get the impression the friend isn't as fussy. He claims it has maybe 30 hrs on it. It started burning oil so he took it to the dealer to get re-ringed. He seems to have a good dealer because he said they are trying to get a new head under warranty. They told him all the seats were damaged and the head is scrap. The friend also had problems with less hours on it, but I'm not sure on the details. This dealer also claims they don't understand why the quads are having this problem because its basicly the same engine as the bike, which leads me to belive they have seen more than just a couple of these.

My first thought is, something got into the engine (maybe muddy water) but why would the dealer try to get it warrantied? I have not even seen these quads, is there a possible poor air filter or inlet seal? He said he uses grease around the seal which he belives the other kid didn't and was talking like that is why the friend lost his engine early.

Anyone else hear of a problem or a fix?

My son had well over thirty hours on his Moto after the first season and the tear-down and rebuild was basicaly a waste of time and money. The motard fifth gear would have cured our only concern.

[Happyboy]

Are the KTMs using Ti valves? Hondas had the same problem where the valves would wear out very quickly but I don't think the seats were taking abuse.

[kdeal]

Harold,

First, you have been very fortunate with your Dales, (a lot of us have). Cannondales have weird issues every once in a while as well, but we as a group have been pretty diligent in finding answers. I have a friend that owns a shop who has three KTMs in there right now with oddball problems. One has been to the local KTM dealer twice before he got it!

I think we have different issues because of riding styles, hours on the bike and how we maintain them. I have a motor in the shop now that looks great on the inside but looks like crap on the outside (he must never clean it and leaves it outside in the weather or cleans it with something too strong).

I don't believe the air filter is the cause of the bad valves and seats (usually the rings are the first to go) and the damage to the valves and seats will not usually burn oil (it should of just had low compression). I think Happyboy maybe on to something, but I agree the valve or the seat take the abuse usually not both.... Possibilities could be too little or too much valve spring pressure or possibly crappy materials. I would have someone that does lots of work on cylinder heads take a look at the old parts and see what they think.

[cannondale27]

The SX motor is a new motor and they put it in quad within a year of it being in the bikes. I think that was to soon and really if the factories want to make a reliable motor they should make it work in a quad first then put it in the bikes. Seems like motors last forever in bikes unless your talking the 250cc 4strokes. The old 525 motor was a proven motor but now its being mass produced. KTM was a rarity in past now Polaris even has those motors. Production has probably tripled since 525 was first brought out. Has to bring up issues. Talk on the forums is KTM has quit production of ATV's, The 50's, 200exc and a few more 2 strokes.

[thedeatons]

The XC engine is their desert proven SOHC engine, and from what I have heard more reliable. I also heard the quad engines have a larger oil sump to deal with the con rod issues the dirtbikes were having....

[MX Quad Dad]

I talked to him today and he said the valves looked perfect. He said he didn't get a look at the head (seats). I think there was more wrong with it (as far as running condition before he took it in) than he told me. He said they took it in because it was burning oil, but today said the compression rings were stuck in on the piston. If this is the case it should have been pretty weak.